Here we have the preparation of matters for the pouring out of the seven vials, which was committed to seven angels; and observe how these angels appeared to the apostle - in heaven; it was in a wonderful manner, and that upon account, 1. Of the work they had to do, which was to finish the destruction of antichrist. God was now about to pour out his seven last plagues upon that interest; and, as the measure of Babylon's sins was filled up, they should now find the full measure of his vindictive wrath. 2. The spectators and witnesses of this their commission: all that had gotten the victory over the beast, etc. These stood on a sea of glass, representing this world, as some think, a brittle thing, that shall be broken to pieces; or, as others, the gospel covenant, alluding to the brazen sea in the temple, in which the priests were to wash (the faithful servants of God stand upon the foundation of the righteousness of Christ); or, as others, the Red Sea, that stood as it were congealed while the Israelites went through; and, the pillar of fire reflecting light upon the waters, they would seem to have fire mingled with them; and this to show that the fire of God's wrath against Pharaoh and his horses should dissolve the congealed waters, and destroy them thereby, to which there seems to be an allusion by their singing the song of Moses, in which, (1.) They extol the greatness of God's works, and the justice and truth of his ways, both in delivering his people and destroying their enemies. They rejoiced in hope, and the near prospect they had of this, though it was not yet accomplished. (2.) They call upon all nations to render unto God the fear, glory, and worship, due to such a discovery of his truth and justice: Who shall not fear thee? Rev 15:4.